Vegetarianism is a complex set of beliefs and practices, spanning from the extreme “fruitarianism,” where people only eat fruits and other plant parts that can be gathered without “harming” the plant, to various forms of “flexitaranism,” like pollotarianism (poultry is okay to eat) and pescetarianism (fish okay). So, what does science have to say about this? What is the ethical case for vegetarianism? And, is it true that vegetarians are more intelligent than omnivores? Not unexpectedly, the answers are complex, so the debate will rage on.

Reader Comments (18)

I determine right and wrong behavior through the application of the golden rule as the foundation of a social contract in dealing with you people. Sneer. This kinda leaves animals on their own. From an aesthetically pleasing standpoint I'd rather see animals happy but since they can't enter an agreed on arrangement with me right and wrong don't apply for animals.

Most of the arguments made on the podcast strike me as elitist. A person who is wealthy enough can choose any diet he/she wishes -- "organic" or "free-range" food or more or less vegetarian diets. But let us take a humanitarian view, by which I mean one that takes into consideration the needs of the poorest amongst us. The other day in the supermarket I bought a chicken for 79 cents a pound, tomatoes for $2.29/lb, a head of lettuce for $2.19, and some apples at $1.89/lb. Consider a poor person who needs to meet his/her family's full nutritional needs at minimal cost. What do you think that person would buy? Would pressures that drove the price of the chicken up improve that family's status?

Thank you so much for this, there is so much woo in this area, that it is refreshing to listen to a rational podcast about the issue. Really appreciated.

I have an issue with your portrayal about the issue of eating fish, I am not sure how much of the jury is out on the issue see If Fish Could Scream by Peter Singer. But even if this is controversial as you claim, isn't the ethical side to err on being cautious (if we have some reasons to think it might be cruel), until we are sure?

You also state that because fish exist naturally, it is more ethical to eat them because the natural death is fairly cruel and inevitable in any case, and you are not adding to the suffering of the animal. By this logic hunting is more ethical than eating farmed meats I suppose, (something I agree with). There is a problem with this argument however, and that is the assumption that the natural world existing is inevitable or good. Let me be clear, I love the natural world, and spend much time in it, but nature is indifferently cruel. Anyone who has seen a lion rip apart an antelope, or a rhino killing off baby calves of another male, would not be hard pressed to say otherwise. This leads to all sorts of issues, of what sort of natural world should we aim for, (man's history interfering with nature has been very poor), but your assumption of just accepting it seems to be poor too.

I found much of the discussion near the end of the podcast pertaining to factory farms vs. smaller production methods to be highly speculative. Not what I can usually expect out of you two. To be rational is to examine the facts and make a conclusion based on them, regardless of where they take you.

Does large scale production produce more bacterial infection per pound of food produced than small scale? Does it cause more environmental damage per pound of food produced than small scale?

I can just as easily speculate that large scale production is more efficient and produces lower impact per pound of food produced. You may be confusing absolute numbers vs. impact per unit of production.

I think a follow up back-ed up by some prior research would be helpful.

I enjoyed listening to the podcast but I think that one main point was missing. The question whether we as humans, percevied other animals on the same scale, all part of evolution, or we believe that we are qualitatively different from them and this warrant different moral values.

I don't get it. What's so hard about understanding that the life of a living organism, any organism, is NOT yours to take. This is undisputedly the highest and best life stance to adopt and is superior to any position espoused by a vegan or vegetarian. I found your rationalizations about why it's okay to kill some forms of life laughable. Your arguments fall flat. Just because plants experience existence differently than we do, and just because they don't have sad eyes/faces, is no reason to flippantly claim their life can be wiped out without the need for a second thought. That's just some screwed up thinking. How about you try thinking twice the next time you shove a healthy stalk of broccoli in your pie hole. We need to do better...you need to do better. And you may want to spend some time reading plant experiential studies rather just pooh-poohing the concept because you think it sounds absurd. It's actually a fascinating field of study.

"What's so hard about understanding that the life of a living organism, any organism, is NOT yours to take. " And why not, Jack? Do sharks get a license before catching their prey? I shall continue to take pleasure in my broadly omnivorous diet without a pang of conscience.

I'm an Archevore (www.archevore.com) which is basically taking cues from the animal-food centric omnivorous diets of most of our ancestral hunter-gatherer cultures and squaring them with modern science. There is no evidence that vegetarianism (especially veganism) is a healthier or as healthy a way of eating as eating meat.

And regarding the morality of meat eating, as a utilitarian, I want to support small, humane, pasture farms and ranches so that the livestock we consume experience comfortable existences, much more comfortable than they could hope for without us caring for them. More animals living better lives because we eat them is a better outcome than their numbers dwindling down to nothing , with the ones surviving living less comfortably in the wild, as a result of vegetarianism.

I try to avoid red meat as much as possible without being impolite in social settings, but I have little sympathy for chickens. I agree that battery cages are a bad idea because they are uncontrolled laboratories for the evolution of new and potentially more deadly human pathogens, but IMHO, the chickens have got it coming. Their ancestors, the dinosaurs, ate our ancestors, now it is our turn to eat them. No ethical problem there! :)

A possibly more rational argument for being an omnivore is that we've evolved to be omnivorous and the species we developed over the centuries are new species which have adapted and benefited in evolutionary terms from their association with humans. Cows, Pigs, Chickens etc. would not survive in the wild. If everyone went completely vegan tomorrow, all those species would go extinct virtually overnight.

Eliminating current undeniably cruel meat production practices would also have a downsides in terms of effects on the environment as vastly more land would have to be devoted to meat production. The Amazon rainforest would have to be totally cleared (for example).

The solution is on the horizon: In vitro meat production where we create factories to produce meat from muscle cells grown in vats without the whole animal being involved. This will still ultimately lead to the extinction of the current food species, but it will solve the cruelty ethical issue and the environmental impact issue.

I'm holding out for that solution. Meanwhile, I'll adopt the 5% or so solution and given a choice will take the least damaging options within an omnivorous lifestyle.

I think that this issue is kinda like slavery was a couple of hundred years ago. There were probably educated slave owners who realized that their lifestyle was unsustainable and hugely unethical. They probably treated their slaves better than most, but didn't free them until they were forced to do so by a general change in the moral landscape.

Fifty years from now, once the meat in a vat technology takes over from current meat production methods, people will probably look back on the current situation as a barbaric age with not a lot to recommend it over the prior era which espoused slavery as a valid economic model.

Respectfully, all vegetarians (and those interested in reading some science on the meat industry) should check out Temple Grandin's web site (http://www.grandin.com). She is not only a university professor, and an ingenious inventor, but she also keeps detailed data on inspections of farms, ranches, and slaughter houses across the country. The picture she paints is FAR different from any you might get from P.E.T.A. or some of the vegan/vegetarian propaganda web sites.

Massimo said that from a labor point of view, the meat and veggie industries are about the same. I think it needs to be pointed out that factory farms feed animals with vegetables! If we ate only vegetables, then we would be decreasing the demand for vegetables as well as meat.

For those who are interested: a complete and consistent ethical system that implies veganism and animal equality: http://stijnbruers.wordpress.com/2013/05/31/e-book-the-ethical-consistency-of-animal-equality/Regarding acute diseases (food poisonings), there has been a comparative study (Adak, G. K., Meakins, S. M., Yip, H., Lopman, B. A. & O'Brien, S. J. 2005. Disease Risks from Foods, England and Wales, 1996–2000. Emerging Infectious Diseases, 11) Animal products have higher hospitalisation risks. The E;coli on spinach is mostly from animal manure. Regarding health of vegan diets: one should compare well-planned vegan diets with well-planned omnivore diets. As omnivore diets innevitably have more saturated fats and cholesterol (and more toxics in fish), I expect that well-planned vegan diets are more healthy than omnivore diets. In any case, the Academy of Nutrition and Dietetics claims that well-planned vegan diets are sufficiently addecuate for everyone. Regarding fish consumption: most likely fish welfare in wild capture is highly underestimated, as the fish can experience long death struggles in the nets (compression, decompression, freezing, stripping, suffocation all take several minutes to more than an hour, longer than most predation). Besides, capturing a fish means a decrease of lifetime well-being, because it means an earlier death. The best scientific summary on fish sentience can be found in EU Food Safety Authority (EFSA), “General approach to fish welfare and to the concept of sentience in fish”, Scientific Opinion of the Panel on Animal Health and Welfare, 2009